1. Field of the Invention
The present invention relates to fastener means for joining two metal panel members and more particularly, to a floating fastener consisting of a mounting base member, a socket, a lock screw, an elastic member and a stop member, which allows a high pre-positioning tolerance, preventing lock screw damage during fastening of the lock screw to lock a first panel member to a second panel member.
2. Description of the Related Art
When joining panel members, fastening devices respectively formed of a screw nail, a rotary knob and a washer may be used. During application, the screw nail, rotary knob and washer of each fastening device are assembled and then mounted at a first panel member. When fastening the first panel member to a second panel member, rotate the rotary knob of each fastening device to drive the respective screw nail into a respective mounting screw hole at the second panel member, and then use a hand tool to fasten tight the screw nail. This multiple panel member fastening method can be used in a machine tool or other situations where multiple panel members are to be fastened in a stack. In a machine tool, the location where panel members are fastened together may be at the power drive or speed-adjustment unit inside the housing.
Further, floating fasteners or floating captive screws are created to facilitate easy installation and removal of attached pieces without release of the screw. Regular floating captive crews commonly comprise a mounting base member, a spring member mounted inside the mounting base member, a lock screw supported on the spring member, and a cap affixed to the head of the lock screw and axially slidably coupled to the mounting base member. During application, the mounting base member is affixed to a mounting through hole on a first panel member. When attaching the first panel member to a second panel member, lower the cap to compress the spring member and to force the lock screw toward a mounting screw hole at the second panel member, and then rotate the cap to drive the lock screw into the mounting screw hole of the second panel member. Thereafter, use a hand tool to fasten tight the lock screw. Further, after disconnection of the lock screw from the mounting screw hole of the second panel member, the first panel member can be removed from the second panel member, and the floating captive screw is kept secured to the first panel member, avoiding missing the component parts.
The aforesaid floating captive screws are intensively used in telecommunication machine cabinets, industrial computers and machine tools to detachably lock panel members of machine cases. However, due to manufacturing tolerances, the mounting through hole at the first panel member may be not kept in accurate alignment with the corresponding mounting screw hole at the attached second panel member. At this time, the lock screw of the floating captive screw at the first panel member may have to be slightly tilted so that it can be driven into the mounting screw hole at the second panel member. However, driving the tilted lock screw into the mounting screw hole at the second panel member in a tilted manner may damage the threads of the lock screw, or cause the lock screw to break.
Therefore, an improvement in this regard is necessary.